PROTOZOA 571 



Trichomonas from amphibia grow better at room temperature, 

 and in a medium containing rather less sodium salts. To these 

 media may be added 1 or 2 c.c, of white of egg, which exerts some 

 bactericidal action. 



Hogue's Egg Medium {At7ier. Journ. Trop. Med., i, 1921, p. 211). 

 A clear medium with a granular sediment made by shaking up a 

 whole egg in a flask with glass beads and adding 200 c.c. Locke's 

 solution. The mixture, kept constantly moving, is heated over a 

 water bath for fifteen minutes and then filtered through cotton- 

 wool. Five to 6 c.c. are placed in each test-tube and sterilised in 

 an autoclave for twenty minutes at 120° C. 



In this, Hogue has obtained pure line cultures of Trichomonas 

 by starting with a single individual. 



Emhadomonas from various sources, as well as Trichomonas, 

 grow well in the medium ; parasites from warm-blooded animals 

 being incubated at 35° to 37° C, while those from cold-blooded 

 animals grow best at ordinary room temperatures. 



Amoebae of cold-blooded vertebrates (turtle and frog) have 

 been cultivated in a very simple medium devised by Barret and 

 Smith (AmiaL Trop. Med. Porasit., xx, 1926, p. 85). It consists 

 of 1 part inactivated human serum and 9 parts of 0-5 per cent, 

 sodium chloride solution. The ^H of this medium is 7-6 to 7-8. 



Entamoeha ranarum is said to grow in media of reactions between 

 pli5 and pHlO though the optimum is between 7 and 8. 



Barret and Yarbrough [Amer. Journ. Trop. Med., i, 1921, 

 p. 161) cultivated Balantidium coli in a more dilute serum, viz., 

 16 parts of the sodium chloride solution to 1 of serum. As a rule, 

 however, sub-cultures had to be made every two days. See also 

 Jameson, § 1120, below. 



Trichomonas of the human mouth and Entamoeha gingivalis 

 multiplied in a mixture of equal parts of ascitic fluid and Locke's 

 solution (Ohira and Noguchi, Journ. Exper. Med., xxv, 1917, 

 p. 341). See also Dobell, § 1120 below. 



Herpetomonas from flies' intestines are best cultivated 

 (Drbohlav, Journ. Parasit., xii, 1926, p. 188) in dilute blood 

 agar provided the |>H is low — 5-6 to 6-4. 



1119. Boeck's Locke-Egg-Serum Medium (L.E.S.) and various 

 modifications devised by Bceck and Drbohlav {Amer. Journ. 

 Hygiene, v, 1925, p. 371) for the cultivation of intestinal protozoa 

 all consist of two parts : a solid and a liquid medium ; the former 

 is prepared in the form of an ordinary bacteriological slope and is 

 more or less covered by the liquid. 



In the original formula the solid medium consists of an emulsion 

 of eggs in Locke's solution (four whole eggs to 50 c.c. solution) 

 coagulated by heating to 70° C. and sterilised in an autoclave at a 

 pressure of 15 lb. for twenty minutes. The liquid medium is a 

 mixture of 1 part inactivated human serum to 8 parts of sterile 



